High school physics education issues as seen by some California teachers: From content standards to critical thinking

Thursday, October 13, 2016

Traffic lights

Years ago while I was at the Exploratorium Teacher Institute an employee came in and had managed to get a bunch of real life traffic lights. They had asked a city worker who was changing them out what they were going to do with them and ended up walking away with a lot. I took home two green and one red and unfortunately left them to sit in a box all these years. I finally managed to check with Zeke Kossover about wiring them up and was surprised to learn that they ran off only 120 V. I had it in my head that they would need much more and I would have to use a transformer. So I bought a heavy duty plug for each light and hooked them up. You can find traffic lights of all varieties on eBay. It was very easy and now I have three giant lights!

I'm not quite sure what I will do with them but I have some ideas:
- Use the red and green lights to indicate to students when to keep working and when to stop on an activity.
- Use the red and green for a giant Colored Shadows demo (I haven't tested if this works yet).
- Have students use light sensors to investigate the light intensity at different distances. I expect that this is bright enough students from all over the classroom will be able to take data off this one light source.

Disclaimer

The views expressed in this blog are those of the post authors and commenters. They are not necessarily those of The San Juan Unified School District, The California Department of Education, Pearson Education (or any of its imprints).